Seat cushion panel and method of manufacturing the same

ABSTRACT

The seat cushion panel of a vehicle is manufactured using a magnesium alloy. The seat cushion panel includes a housing panel having a reinforcing means molded thereto.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on, and claims priority to Korean Application No. 2004-0031066, filed on May 3, 2004, the disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

This invention relates to a seat cushion panel of a vehicle manufactured using a magnesium alloy and a method of manufacturing the same.

BACKGROUND OF THE INVENTION

In recent years, as vehicles become more and more luxurious, and there are increasing requirements for vehicles to comply with the traffic laws and safety regulations along with vehicle owners' conveniences, the seats of a vehicle tend to become heavier. Therefore, as a way to reduce the weight of a seat, seat frames have been manufactured using light-weight materials instead of more traditional steels. More specifically, the seat frames made of a magnesium alloy by means of a high pressure casting method are advantageous in that repeated mass production is possible. These seats also make it possible to significantly reduce noise levels through dimensional accuracy. In addition, because seat cushion panels are installed on the top of a base they barely affect the safety evaluations of these seats. Further, being of a rather simple shape, the seat cushion panels can be manufactured using steel materials by means of a press and then connected to other auxiliary parts by welding.

In the event that a magnesium alloy having relatively poor physical properties compared to that of a steel is selected, it is essential that a design planning considering the above deficiency be performed in advance. It is also possible to design a structure that is better than steel products when the manufacturing process also reflects the casting point of view. However, the seat cushion panel for the press method using steel materials essentially requires a notched area at the time of casting a curved portion of a housing panel, which has a drawback in that it is highly vulnerable to concentrated stress and often causes a breakage. Accordingly, a design that addresses the above drawbacks would be highly desirable.

SUMMARY OF THE INVENTION

This invention provides a reinforcing means of a round shape which is applicable only to a high pressure casting process in molding a seat cushion panel adapted to replace the notched part present in a conventional press molding, where stress is concentrated, thereby improving the quality of products.

This invention further provides a switch bracket, which is employed in a motor-driven seat, with a clip-inserting structure for its installation instead of a conventional welding method, thereby reducing the number of steps in a molding process required for manufacturing a seat cushion panel of a vehicle.

This invention further provides a magnesium alloy seat cushion panel of a vehicle wherein the area for installing S spring is designed in a supportive structure where both ends are closed unlike the conventional ones where one end is open, thereby increasing the fatigue endurance strength.

This invention further provides a method for manufacturing a magnesium alloy seat cushion panel of a vehicle, wherein a casting gate is provided in the center of a mold so that the molten metal can be dispersed at various directions to be flowed into a mold at the time of a casting via a die casting process to enable a high pressure casting.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention will become apparent from the following description of the invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a part of the seat cushion panel of a vehicle made of a magnesium alloy according to an embodiment of the present invention, wherein the notched part in the conventional steel press product is replaced with a round shape;

FIG. 2 is a perspective view of a part of the seat cushion panel of a vehicle made of a magnesium alloy according to an embodiment of the present invention, wherein an area for installing the conventional S spring with one open end is replaced with one with both ends closed;

FIG. 3 is a perspective view of a clip-inserting structure of a switch bracket of a seat cushion panel of a vehicle made of a magnesium alloy according to an embodiment of the present invention; and

FIG. 4 shows perspective views for the flow of molten metal over time and the location of a gate installation at the time of casting a seat cushion panel of a vehicle made of a magnesium alloy, according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

This invention relates to a seat cushion panel of a vehicle manufactured using a magnesium alloy and a method of manufacturing the same. More particularly, this invention relates to a seat cushion panel of a vehicle manufactured using a magnesium alloy and a method for manufacturing the same, wherein the properties of a magnesium alloy used for manufacturing the conventional steel press seat cushion panels are particularly reinforced while its advantageous properties such as light-weight and easy castability are much improved.

In an embodiment of the present invention, there is provided a reinforcing means in a certain part of the housing panel 10 to overcome the problem of concentrated stress being loaded on a certain portion of the housing panel 10 that is known to be vulnerable to the concentrated stress. The above reinforcing means includes a reinforcing means 11 having a round shape mounted on the curved portion of the housing panel while a spring mounting element having a supportive structure with both ends closed is formed on the area where the S spring is to be mounted.

In another embodiment of the present invention, there is provided a clip-inserting structure in the housing panel 10 so that a switch bracket 13 (FIG. 3), which is employed in a motor-driven seat, can be readily fixed.

In a further embodiment of the present invention, there is provided a casting gate 20 (FIG. 4) installed in the center of a mold so that a molten metal can be dispersed in various directions and flow through the casting gate 20 at the time of molding via a die casting process.

In a further embodiment of the present invention, the molten metal is introduced at the rate of 4.0-5.0 m/sec under the virtual pressure of 600 bar, wherein the sleeve is formed to have a diameter of 100 mm.

The present invention is further illustrated with reference to the accompanying drawings as set forth hereunder.

FIG. 1 shows a part of the seat cushion panel of a vehicle made of a magnesium alloy according to an embodiment of the present invention, wherein the notched part present in the conventional steel press product is converted to be round in shape. FIG. 2 shows a part of the seat cushion panel of a vehicle made of a magnesium alloy according to an embodiment of the present invention, wherein an area for installing the conventional S spring with one open end is replaced with that having both ends closed. FIG. 3 shows a clip-inserting structure of a switch bracket in the seat cushion panel of a vehicle made of a magnesium alloy according to an embodiment of the present invention.

As stated above, this invention relates to a magnesium alloy seat cushion panel of a vehicle wherein a conventional steel seat cushion panel prepared by pressing is replaced with a magnesium alloy prepared by a high pressure casting process. This rectifies mechanical properties while accompanying the conversion of its shape, and adds a rectifying means and improvement in the location of a casting gate.

The physical properties of the magnesium alloy used in manufacturing the seat cushion panel of a vehicle of the present invention are greatly reinforced, in particular with respect to its mechanical strength, by means of changing the shape, adding a new reinforcing means and improving the location of installing a casting gate, while maintaining the superior intrinsic properties of the magnesium alloy having a light-weight.

As shown in FIG. 1, the seat cushion panel of this invention is designed to use all the parts prepared and used in a conventional pressing method for manufacturing the same. In particular, there is introduced a change in shape of a mold 15 for manufacturing the seat cushion panel of a vehicle so that the equal strength can be maintained in the seat cushion panel manufactured using the magnesium alloy of this invention as to that of the conventional steel made seat cushion panel. That is, a notched part, the particular part of the conventional seat cushion panel which is relatively vulnerable to concentrated stress, is replaced in this invention with a reinforcing means having a round shape.

Further, in installing a switch bracket which is fixed to a motor-driven seat of a vehicle, the conventional method of fixing between steel materials, welding is replaced by a clip-inserting structure, which is more appropriate to a magnesium alloy product. This reduces the production time and cost by reducing the number of processing steps.

Further, the spring mounting part 12 (FIG. 2), where the S spring is to be mounted, is designed with a supportive structure where both ends are closed unlike the conventional supportive structure where one end is open. Therefore, the seat cushion panel of a vehicle manufactured using a magnesium alloy according to this invention can achieve equally powerful physical properties as those manufactured using the conventional steel material while still maintaining the advantage of having light weight. Meanwhile, the step of forming a seat cushion of a vehicle is the most critical step to reflect a given design at its optimum level. In particular, the optimization of a casting process is one of the essential steps of this invention. In forming a seat cushion panel using a magnesium alloy, a solidification process can be performed rapidly under the optimized condition of a casting gate. Therefore, the casting should be performed using a high speed die casting process, and accordingly, it is essential to select a most appropriate location for installing a casting gate via rheological analysis.

That is, when a molten metal fills in a certain area with limited space through a rather complex passage, the way of filling-in differs greatly depending on from which location the molten metal is introduced, and preferred embodiments can be derived based on the variations of the location.

FIG. 4 shows the flow of molten metal over time and the location of a gate installation at the time of casting a seat cushion panel of a vehicle made of a magnesium alloy, according to an embodiment of the present invention. In the process of molding a seat cushion panel of a vehicle, as shown in the FIG. 4, molten metal flows into a nearby area to uniformly fill-in the area. When a casting gate 12 is installed in the center of the mold 15, the molten metal disperses in various directions, thereby firstly filling in the very end of the mold instead of being united in the middle. This reduces occurrences of casting defects. In this way, the insertion time of the molten metal into a mold is significantly reduced as compared to that of a conventional insertion time, and is thus suitable for using a magnesium alloy material which solidifies rapidly. When the molding is performed using the aforementioned molding process, it is preferable to have an insertion rate of about 4.0-5.0 m/sec for a molten metal through the casting gate 20, and virtual pressure of about 600 bar wherein the sleeve preferably has a diameter of about 100 mm.

The optimal forming conditions in this invention were obtained as a result of numerous experiments by varying the forming conditions and it will be very difficult to obtain a good quality product without any unformed portion even under a desirable gate strategy. Therefore, in the event of a casting according to this invention where molten metals are allowed to be united, it can prevent casting defects due to gas entrapment in the mold or by the presence of a hot flow of the molten metals, thereby enabling to maximally mold a seat back frame of a vehicle to a maximum level.

The invention has been described in detail with reference to preferred embodiments thereof. However, it will be appreciated that those skilled in the art, upon consideration of the disclosure, may make modifications and improvements within the scope and spirit of the invention. 

1. A seat cushion panel of a vehicle manufactured using a magnesium alloy comprising a housing panel, wherein a part of the housing panel, which is vulnerable to concentrated stress, is provided with a reinforcing means integrally molded thereto for the purpose of releasing stress.
 2. The seat cushion panel of a vehicle manufactured using a magnesium alloy according to claim 1, wherein said reinforcing means comprises: a round reinforcing means positioned at the curved portion of said housing panel; and a spring mounting element with closed supportive ends positioned at a S spring mounting portion.
 3. The seat cushion panel of a vehicle manufactured using a magnesium alloy according to claim 1, wherein a switch bracket employed in a motor-driven seat is further attached to said housing panel by means of a clip-inserting structure.
 4. A method of manufacturing a seat cushion panel of a vehicle manufactured using a magnesium alloy, wherein a casting gate is installed in the center of a mold so that a molten metal, in the course of molding via die casting, is dispersed at various directions and flowed into said mold, wherein said molten metal is flowed into said mold at the rate of about 4.0-5.0 m/sec under the virtual pressure of about 600 bar, wherein the diameter of the sleeve is about 100 mm.
 5. A seat cushion panel of a vehicle, comprising: a seat cushion housing panel manufactured using a magnesium alloy and provided with a reinforcing mechanism integrally molded thereto for the purpose of releasing stress.
 6. The seat cushion panel according to claim 5, wherein said reinforcing mechanism comprises: a round reinforcing mechanism is positioned at the curved portion of said housing panel; and a spring mounting element with closed supportive ends at a spring mounting portion.
 7. The eat cushion panel according to claim 5, wherein a switch bracket employed in a motor-driven seat is further attached to said housing panel by means of a clip-inserting structure. 